Stapling machine



Dec. 27, 1949 A. A. vANDERvlERx-:N 2,492,509

STAPLING MACHINE mwym-M Dec. 27, 1949 A. A. VANDERVIEREN STAPLING MACHINE Filed Feb. 11, 1946 frwenlr Patented Dec. 27, 1949 ill,

Aim Albert Vandervieren, Berkhamsted, England Application February 11,

In Great Britain October 30,

4 Claims.

The present invention relates to a machine for driving staples into material, such machine being of the kind comprising a reciprocating plunger for driving the individual staples into the work, the plunger being moved upwardly by a handoperated lever, and moved downwardly under the action of a spring.

According to the present invention the m'ovements of the operating lever are transmitted to the plunger through the medium of a single link and a single subordinate lever. The latter is provided with a projecting nose that engages beneath the base of the plunger during the upward movements of the latter.

The subordinate lever is adapted to be displaced about a xed pivot secured to the frame of the machine, the lever having a curved slot that engages the Xed pivot, the arrangement being such that at the commencement of the upward movement of the plunger the slot is displaced relatively to the fixed pivot in such manner that the elective length of the lever is decreased with the result that the nose of the lever is disengaged from' the base of the plunger, and the latter is free to descend.

One form of construction of the invention is illustrated in the annexed drawings, in which:

Figs. l-3 are side elevations partly in section, Fig. 1 shows the subordinate lever in its normal position with its nose beneath the base of the plunger.

Fig. 2 shows the lever about to be disengaged from the plunger, and Fig. 3 shows the lever entirely disengaged.

Fig. 4 is an end view.

In these drawings a is a plunger movable in a cylinder b under the action of a spring c, the plunger carrying a blade d which performs the dual function of severing a staple from a clip of staples and forcing it into the work. The staples travel along a guideway e in a base member f. The parts so far described are all of known construction, as is a hand-operated lever g connected by a strong spring I1. to a frame member i, the operating lever having a xed pivot lc. A single link Z is connected to the lever g by means of a moving pivot m and to a single subordinate lever n by a further moving pivot o. The lever n is provided with a spring s, and with a curved 1946, Serial No. 646,765

slot p of which one end engages a pivot q secured to a frame member r.

The action of the device is as follows: In the normal or starting position, shown in Figure 1, the nose of the lever n bears beneath the base of plunger a. When the lever g is elevated to approach frame member g', it pivots about the xed pivot Ic thus compressing spring h. As the lever g is elevated, the connecting link Z and trigger lever n are also raised, the lever n pivoting and sliding about pivot q. During this elevating motion, the nose of the lever n which is in engagement with the base of the plunger a raises same thus compressing spring c within cylinder b. As the lever g continues to raise, the lever pivots about q upwardly in a clockwise direction as viewed in Figure 2, thus shortening the eilective length of the lever thus allowing disengagement of the nose of the lever n from the base of the plunger a at which time it moves beyond the path of the plunger a and allows same to be driven downwardly by the action of spring c thus lowering blade d and driving the staple into the work. The return movement, as shown in Figure 3, is completed by the lowering of lever g thus causing the link l to rotate the lever n about pivot q until the action of the counter-clockwise rotation of lever n permits the spring s to cause the lever n to assume the position shown in Figure 1 at which time the nose of lever n is beneath the plunger a and is ready to commence another operational cycle.

I claim:

1. A stapling machine comprising a frame, a spring-biased plunger movably mounted in said frame, a fixed fulcrum in said frame, a subordinate lever having a free end adapted to engage and move said plunger in opposition to its spring bias and also having a slot slidable over said iulcrum, said slot comprising upper and lower sections intersecting angularly, an operating lever pivotally mounted in said frame, a link pivotally connecting said levers, and a stapledriving blade carried by said plunger.

2. A stapling machine as claimed in claim 1 in which the slot sections are disposed at an obtuse angle.

3. A stapling machine as claimed in claim 1 wherein means are provided for normally holding the fulcrum in the end of the subordinate lever against the lower end of the slot therein.

4. A stapling machine comprising a frame, a. spring-biased plunger movably mounted in said frame, a xed fulcrum in said frame, a subordinate lever having a free end adapted to engage said plunger in opposition to its spring bias and also having a slot slidable over said fulcrum, said slot comprising upper and lower sections intersecting angularly, an operating lever pivotally mounted in said frame, means for connecting said levers, and a staple-driving blade carried by said plunger.

AIME ALBERT VANDERVIEREN.

REFERENCES CITED The following references are of record in the le of this patent:

4 UNITED STATES PATENTS Number Name Date Palmgren July 15, 1913 Michener June 5, 1923 Polzer May 6, 1930 La Place Apr. 28, 1931 Crofoot Feb. 12, 1935 Polzer Mar. 23, 1943 Krantz Aug. 10, 1943 Wheeler Apr. 18, 1944 Lang Oct. 31, 1944 

